After-Hours Buzz: Gap, Dell, H&R Block & More

Check out which companies are making headlines after the bell Thursday:

Gap - The clothing retailer posted same-store sales that gained 7 percent in June, exceeding expectations for an increase of 4.7 percent, according to estimates from StreetAccount. Shares climbed in extended-hours trading.

(Read More: Dow, S&P End at Record Highs as Stocks Spike 1%)

Dell - Billionaire investor Carl Icahn is expected to announce a bid that will be "vastly superior" to Michael Dell's offer for the tech company on Friday morning, according to reports. Dell shares edged higher in extended-hours trading.

H&R Block - The tax preparer said it will sell certain assets and liabilities of H&R Block Bank to Republic Bank and Trust. The agreement is subject to regulatory approvals. Shares were largely unchanged in extended-hours trading.

Aveo Pharmaceuticals - The drugmaker disclosed that it received a subpoena from the SEC earlier this month requesting documents and information regarding tivozanib, a treatment for patients with advanced renal cell carcinoma. Shares plunged in extended-hours trading.

Advanced Micro Devices - The chipmaker slipped in extended-hours trading after soaring nearly 12 percent during the regular session.

—By CNBC's JeeYeon Park (Follow JeeYeon on Twitter: @JeeYeonParkCNBC)

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