M&A & Investments Costa Rican regulator Sutel has rejected a planned merger between operators Liberty and Tigo. This scraps plans from parent companies Liberty Latin America and Millicom International Cellular to combine their local operations. SoftBank has doubled down on its OpenAI investments by selling Nvidia and T-Mobile shares to invest a total of $30 billion in OpenAI. The Japanese tech company’s share price has been extremely volatile in recent weeks as a result of its close coupling with the AI sector. SoftBank is so deeply invested in OpenAI that investors view it as a proxy for the AI firm. Israeli telco Bezeq has secured an agreement with local operator Hot’s mobile arm, Hot Mobile, for ILS 2.1 billion ($650…