Apple has found a big investor that still has faith in its future: itself.

On Tuesday, the technology giant announced that it planned to more than double its program to return cash to shareholders through stock buybacks and a higher dividend, spending $100 billion on the effort through the end of 2015. Its share repurchases alone will increase to $60 billion from the $10 billion it committed previously, the largest such plan in history, the company said.

The move to renew investors’ love affair with Apple’s stock came as the company announced its first profit decline in a decade. Apple said its net income fell 18 percent in its fiscal second quarter, as one of the most successful technology franchises in recent years, the iPhone, showed signs of slowing and other, less profitable products began to make up more of its sales.

The rarity of Apple’s profit decline, which was expected, underscores how one of the most remarkable winning streaks in business has come to an end, at least for now. Investors have battered the company’s stock for months, sending its shares down from their peak of more than $700 last year as warning signs began to emerge about its growth prospects.

In regular trading on Tuesday, Apple shares rose nearly 2 percent to close at $406.13, but they fell slightly in after-hours trading as investors digested the quarterly earnings news and Apple’s plan to return cash to shareholders. One thing that spooked investors is that Apple told them to expect little to no sales growth in this quarter.