Twitter's board of directors may consider Dick Costolo's exit to make it easier for the next CEO to run the company. Reuters

Twitter Inc. is considering a major board shakeup, which could include the exit of the company’s former CEO Dick Costolo, a report said Friday. The San Francisco-based social media company is likely to announce the changes to its board of directors once Costolo’s permanent replacement is hired.

The move is part of Twitter’s attempt to make the board more diverse, with the inclusion of directors from different backgrounds, such as minorities and those from adjacent industries, including advertising and e-commerce, Bloomberg reported, citing people familiar with the matter.

In its present state, Twitter’s board includes three former CEOs -- Jack Dorsey, Ev Williams and Costolo -- an issue that could make it difficult for the new CEO to run the company. To address this concern, the board would consider replacing Costolo, the source told Bloomberg.

Twitter named co-founder Dorsey as the company’s interim CEO after Costolo resigned from the top job on July 1. Other than Dorsey, possible candidates for the company’s next CEO include Ross Levinsohn, former CEO of Yahoo!; Mike McCue, CEO of newsreader app company Flipboard; Kevin Systrom, the founder of Instagram; and Evan Williams, CEO of blogging website Medium, Reuters reported.

According to a recent study conducted by a California-based company Equilar, which tracks executive compensation, no company in the S&P 500 index has three of its former CEOs on its board of directors. Williams also recently said at a conference that he would step down if the new CEO does not want to have three former bosses on the board, the Wall Street Journal reported.

Last week, Twitter said that its monthly average user base in the second quarter of 2015 grew at the slowest pace since it went public in 2013. According to the company, user growth was up 2.6 percent to 316 million, a deceleration from last quarter.