Sen. Elizabeth Warren has entered the private listings battle.
The ranking member of the Senate Committee on Banking, Housing and Urban Affairs sent a letter late last week to Compass CEO Robert Reffkin and MRED MLS CEO Rebecca Jensen requesting information about the partnership between the two entities.

Sen. Elizabeth Warren, D-Mass.
While the Massachusetts Democrat is in the minority in the Senate, the letter is a signal that key members of Congress remain focused on the ongoing consolidation wave in real estate and the ongoing debate around off-MLS marketing.
“Your partnership threatens to create a two-tiered housing market where insiders pay for exclusive access to housing inventory and market data, while everyone else is shut out,” Warren wrote in her letter, which was dated Aug. 6.
The letter was first reported on by Realtor.com on Friday.
In addition to creating gated access to housing information, Warren said that she feared the partnership “will increase industry consolidation and harm consumers by driving up housing costs and worsening inequalities in the housing market.”
She asked the companies to explain what they’ve done to mitigate potential harms of the partnership.
Warren’s letter specifically referenced the partnership announced in late April, when MRED said it would offer its private listing network to any agent that wanted to join the MLS, even those who were far outside the MLS’s typical Midwest footprint.
As part of the partnership, Compass said that it would subsidize the cost of joining for up to 100,000 agents, and that it would provide its listings inventory to MRED.
Around the same time, Compass brands were moving to sever its feed of listings to Zillow, creating a threat to the for-sale inventory that powers the nation’s largest search portal.
Several other MLSs followed suit, including Bright MLS, Realtracs and The MLS CLAW in southern California.
Warren’s office didn’t respond to a request for comment. Neither did Compass International Holdings.
In a statement provided to Inman, an MRED representative said that the MLS looked forward to working with Warren.
“It would be an honor to speak with Senator Warren and explain the important role of the MLS in the real estate marketplace,” the representative said. “Issues such as fair housing, data quality and rules are critical to any MLS. We look forward to discussing MRED’s value with her.”
This isn’t the first time Warren has poked around some of the largest forces in the real estate industry.
Last December, Warren sent a letter to the DOJ and Federal Trade Commission urging them to “closely scrutinize” what was then a proposed merger between Compass and Anywhere Real Estate.
She and Sen. Ron Wyden, D-Ore., at the time said that the merger could threaten competition in the real estate industry.
The merger was approved and closed in January, creating the largest enterprise in the real estate industry by far.
Warren was the only senator to sign the letter sent last week.