Broadcom said Friday that it has begun reaching out to Qualcomm shareholders to secure their votes to replace the San Diego company's broad members, the latest maneuver in its hostile takeover attempt of the smartphone chip maker.

The announcement means that the semiconductor company, led by Hock Tan, has officially filed its proxy materials with the Securities and Exchange Commission, and is in the process of mailing a letter and blue voting card to Qualcomm shareholders.

"At Qualcomm's Annual Meeting of Stockholders on March 6, 2018, you will have an important opportunity to influence the value of your investment by voting the BLUE proxy card for 11 independent and highly qualified individuals," Broadcom said in the letter.

The letter follows a series of back-and-forth jabs between the two companies, which started in November when Broadcom made an unsolicited bid to buy Qualcomm for $70 a share. Qualcomm's board rejected the buyout offer. The rebuff prompted Broadcom to challenge all 11 members of Qualcomm's board with its own nominees.

In December, Qualcomm publicly spurned the proposed nominees, adding that it would not include ballots for the candidates in shareholder documents filed with the SEC.

Friday's formal communication with Qualcomm shareholders was the expected next step for Broadcom as it solicits votes ahead of the shareholder meeting.

Qualcomm also filed its definitive proxy materials on Friday, officially inviting shareholders to its annual meeting of stockholders at 8 a.m. on March 6.

"The Board believes that (Broadcom's board) nominees are inherently conflicted and lack the skills and experience necessary to run a large capitalization, highly complex, and technology and innovation-driven global corporation like ours," Qualcomm CEO Steve Mollenkopf wrote in a letter to shareholders.